The purpose of this library is to read tcpdump trace files with the ability to
navigate around in the file between reads.
The API is intentionally much like that of the pcap library.
You can navigate in trace files both in time and space: you can jump to a
packet which is at appr. 2/3 of the trace, or you can jump as closely as
possible to a packet with a given timestamp, and then read packets from
there. In addition, the API provides convenience functions for manipulating
timeval structures.